This invention relates to a presettable dynamic delay flip-flop circuit, and more particularly to a binary counter used with, for example, a ripple carrier type programmable counter capable of freely presetting a count scale number by means of a program input.
A widening range of applying an integrated circuit (abbreviated as "IC") has made it necessary to develop a programmable counter capable of being operated at a higher frequency. An IC device formed of bipolar transistors can indeed meet a demand for a high frequency counter, but has the drawbacks that it consumes a great deal of power, has a low degree of integration, and is found unadapted for large scale integration (abbreviated as LSI). To resolve these problems, an insulated gate field effect transistor (abbreviated as "IGFET") is generally used for the purpose of LSI. However, an LSI device of IGFET's has an inferior frequency characteristic to an LSI device of bipolar transistors.
The prior art programmable counter includes, for example, a synchronization type counter comprising a J-K flip-flop circuit and a ripple carrier type counter including a delay type flip-flop circuit. These known programmable counters must always be provided with a static binary counter including a feedback circuit to prevent the erroneous operation of the counter circuits, and consequently makes it impossible to decrease a number of circuit elements by applying a dynamic binary counter. Further, any of the known programmable counters has a complicated circuit arrangement and an undesirable frequency characteristic.